This epidemiologic study of endometrial cancer monitors the incidence, severity, and mortality trends in a sample of cases reported to the New York State Cancer Registry during the years 1971 through 1981. Cases will be validated through histologic re-examination and re-staging of this sample. This will indicate if incidence is increasing for both advanced and early stages of the disease, and what effect this may have on future mortality rates. The epidemiologic case-control component of the research focuses on the association between endometrial cancer and the use of estrogens. Specifically, we wish to determine if estrogen use is associated with advanced stage disease, and if there is a risk decline following termination of use. Additionally, we will ascertain through multivariate methods the factors which discriminate low grade and/or early stage cases from high grade, advanced stage cases. One hundred and fifty advanced stage and 200 early stage newly diagnosed endometrial cancer patients will be interviewed. A case to control ratio of 1:2 for advanced stage cases and 1:1 for early stage cases will be used.